1. Field of the Invention
The present invention relates to an annular spider (damper) with lead wires sandwiched, and in particular to an improved spider structure with lead wires sandwiched in between two surface linings, using a specially designed press mould without causing damage or deformation to the lead wires in the press forming.
2. The Related Art
Conventional moving coil speakers include the following components: a speaker driver, a diaphragm, and a suspension system. The speaker driver is composed of an electromagnet, pole pieces, pole plates, an air gap, and a voice coil unit. The diaphragm or speaker cone is the actual component that is responsible for converting the electrical signals into audible sound. The suspension system is composed of an annular spider and an edge support, where the spider is responsible for guiding the motion of the speaker cone in a longitudinal direction. The speaker driver, speaker cone and suspension system are housed in a cone housing.
The voice coil is connected by lead wire to a terminal that is disposed on the outer peripheral wall of the cone housing. When electrical signals are passed through the terminal and the lead wire to the voice coil, a magnetic field is created in response to the input signal, which is perpendicular to the line of force of the electromagnet, so the voice coil will cause the speaker cone to travel through the air gap in the longitudinal orientation. The movement of the speaker cone displaces the air in the vicinity of the cone, and creates sound waves having an amplitude and frequency to match the electrical signals. In this manner the desired audible sound reproduction is achieved.
In the conventional speaker shown in FIG. 1, the terminal B is disposed on the outer peripheral wall of the cone housing D; the voice coil C is mounted between the pole plate and the pole piece in the center. The lead wires 2 are connected across the annular spider A to reach the voice coil C as shown in FIG. 2, wherein the lead wires 2 are constantly being stretched whenever the voice coil and the speaker cone travel downward, so the wire material will experience material fatigue over an extended period, which will cause the wire to break off eventually.
One possible solution is to have the lead wires 2 buried in the spider 1 when the spider 1 is press formed as shown in FIG. 3, and only have the two ends exposed outside the inner rim and outer rim. However, in the press forming of the spider, the lead wires 2 composing of two sheets of fabric materials Al, A2 could be damaged or deformed when the two mould halves are pressed together. If the result is partially deformed wires, the quality of sound reproduction of the loud speaker system could be affected.